Composition of hard lead alloys.



FRANCIS C. FRARY, 0F MINNEAPOLIS, AND STERLING N. TEMPLE, OF ST. EAUL,MINNESOTA; SAID TEMPLE ASSIGNOR OF ONE-SIXTH OF THE OLE RIGHT T0Patented Nov. 2, 1915.

SAID FRARY.

P COMPOSITION OF HARD LEAD ALLOYS 1 158 675 Specification of LettersPatent.

No Drawing.

To all whom it may concern:

Be it known that we, FRANCIS O. FRARY andS'rERmNe N. TEMPLE, citizens ofthe United States, and residents, respectively, of Minneapolis, in thecounty of Hennepin and State of Minnesota, and St. Paul, in the countyof Ramsey and State of Minnesota, have invented certain new and usefulImprovements in the Composition of Hard Lead Alloys, of which thefollowing is a specification. r A

Our invention has for its object to provide an improved form of hardlead alloy, adaptable to the customany uses of such alloys.

In order to obtain the necessary hardness and other properties, it hasbeen customary to add a considerable proportion of antimony to the lead.This is at present expensive as compared with lead, and moreover so muchof it must be used that the specific gravity of the alloy is very muchreduced thereby. For the manufacture of bullets and ammunition it isvery desirable to obtain a hard alloy or the maximum specific gravity,in order to concentrate the maximum of kinetic energy in the minimum ofvolume.

In carrying out ourinvention we use a very small amount of metallicmagnesium in a main body of lead. We find that a very small amount ofmagnesium has as great a hardening eflect as a much greater quantity ofantimony, and that less than one per cent. of magnesium is sufficient toproduce a hard lead alloy of commercial value. We have also found thatthe alloy containing a small amount of magnesium is improved by theaddition of a small amount of metallic cop per. This causes the alloy tobe very tough, and not have the brittleness which characterizes ordinaryantimonial lead.

Application filed August 13, 1915. Serial No. 45,379.

We have obtained the best results with alloys containing one-half percent. of magnesium, or one-half per cent. of magnesium and one-fourth toone-half per cent. of copper. These alloys are very hard, tough, andhave a high specific gravity.

-What we claim is:

1. As a new'article of manufacture, hardlead alloys containing inaddition'to a main body of lead, a small amount of metallic magnesium.

2. As a new article of manufacture, a

metallic alloy having a main body of lead FRANCIS C. FRY.

Witnesses:

Amen W. Fnanr, W. KRITCHEVSKY. Signed at Morristown, day of August,1915.

STERLING N. TELE.

Witnesses:

J. C. TEMrLE, ISABELLE M. Tnmirm

